// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/device_sensors/data_fetcher_shared_memory.h"

#include "base/logging.h"
#include "base/metrics/histogram_macros.h"

namespace {

bool SetMotionBuffer(content::DeviceMotionHardwareBuffer* buffer,
    bool enabled)
{
    if (!buffer)
        return false;
    buffer->seqlock.WriteBegin();
    buffer->data.allAvailableSensorsAreActive = enabled;
    buffer->seqlock.WriteEnd();
    return true;
}

bool SetOrientationBuffer(
    content::DeviceOrientationHardwareBuffer* buffer, bool enabled)
{
    if (!buffer)
        return false;
    buffer->seqlock.WriteBegin();
    buffer->data.allAvailableSensorsAreActive = enabled;
    buffer->seqlock.WriteEnd();
    return true;
}

bool SetLightBuffer(content::DeviceLightHardwareBuffer* buffer,
    double lux)
{
    if (!buffer)
        return false;
    buffer->seqlock.WriteBegin();
    buffer->data.value = lux;
    buffer->seqlock.WriteEnd();
    return true;
}

} // namespace

namespace content {

DataFetcherSharedMemory::DataFetcherSharedMemory() { }

DataFetcherSharedMemory::~DataFetcherSharedMemory()
{
}

bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer)
{
    DCHECK(buffer);

    switch (consumer_type) {
    case CONSUMER_TYPE_MOTION:
        motion_buffer_ = static_cast<DeviceMotionHardwareBuffer*>(buffer);
        UMA_HISTOGRAM_BOOLEAN("InertialSensor.MotionDefaultAvailable", false);
        return SetMotionBuffer(motion_buffer_, true);
    case CONSUMER_TYPE_ORIENTATION:
        orientation_buffer_ = static_cast<DeviceOrientationHardwareBuffer*>(buffer);
        UMA_HISTOGRAM_BOOLEAN("InertialSensor.OrientationDefaultAvailable",
            false);
        return SetOrientationBuffer(orientation_buffer_, true);
    case CONSUMER_TYPE_ORIENTATION_ABSOLUTE:
        orientation_absolute_buffer_ = static_cast<DeviceOrientationHardwareBuffer*>(buffer);
        return SetOrientationBuffer(orientation_absolute_buffer_, true);
    case CONSUMER_TYPE_LIGHT:
        light_buffer_ = static_cast<DeviceLightHardwareBuffer*>(buffer);
        return SetLightBuffer(light_buffer_,
            std::numeric_limits<double>::infinity());
    default:
        NOTREACHED();
    }
    return false;
}

bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type)
{
    switch (consumer_type) {
    case CONSUMER_TYPE_MOTION:
        return SetMotionBuffer(motion_buffer_, false);
    case CONSUMER_TYPE_ORIENTATION:
        return SetOrientationBuffer(orientation_buffer_, false);
    case CONSUMER_TYPE_ORIENTATION_ABSOLUTE:
        return SetOrientationBuffer(orientation_absolute_buffer_, false);
    case CONSUMER_TYPE_LIGHT:
        return SetLightBuffer(light_buffer_, -1);
    default:
        NOTREACHED();
    }
    return false;
}

} // namespace content
